Struct DebugStepsWalker

struct DebugStepsWalker<'a> {
    node: &'a mut CallTraceNode,
    current_step: usize,
    stack: Vec<(String, usize)>,
    sources: &'a ContractSources,
    contract_name: &'a str,
}

Walks through the [CallTraceStep]s attempting to match JUMPs to internal functions.

This is done by looking up jump kinds in the source maps. The structure of internal function call always looks like this: - JUMP - JUMPDEST … function steps … - JUMP - JUMPDEST

The assumption we rely on is that first JUMP into function will be marked as [Jump::In] in source map, and second JUMP out of the function will be marked as [Jump::Out].

Also, we rely on JUMPDEST after first JUMP pointing to the source location of the body of function which was entered. We pass this source part to parse_function_from_loc to extract the function name.

When we find a [Jump::In] and identify the function name, we push it to the stack.

When we find a [Jump::Out] we try to find a matching [Jump::In] in the stack. A match is found when source location of the JUMP-in matches the source location of final JUMPDEST (this would be the location of the function invocation), or when source location of first JUMODEST matches the source location of the JUMP-out (this would be the location of function body).

When a match is found, all items which were pushed after the matched function are removed. There is a lot of such items due to source maps getting malformed during optimization.

Fields

node: &'a mut CallTraceNode

current_step: usize

stack: Vec<(String, usize)>

sources: &'a ContractSources

contract_name: &'a str

Implementations

impl<'a> DebugStepsWalker<'a>

pub fn new( node: &'a mut CallTraceNode, sources: &'a ContractSources, contract_name: &'a str, ) -> Self

fn current_step(&self) -> &CallTraceStep

fn src_map(&self, step: usize) -> Option<(SourceElement, &SourceData)>

fn prev_src_map(&self) -> Option<(SourceElement, &SourceData)>

fn current_src_map(&self) -> Option<(SourceElement, &SourceData)>

fn is_same_loc(&self, step: usize, other: usize) -> bool

fn jump_in(&mut self)

Invoked when current step is a JUMPDEST preceded by a JUMP marked as [Jump::In].

fn jump_out(&mut self)

Invoked when current step is a JUMPDEST preceded by a JUMP marked as [Jump::Out].

fn process(&mut self)

fn step(&mut self)

pub fn walk(self)

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 64 bytes